首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   20970篇
  免费   1622篇
  国内免费   57篇
耳鼻咽喉   297篇
儿科学   655篇
妇产科学   458篇
基础医学   2980篇
口腔科学   328篇
临床医学   2008篇
内科学   3996篇
皮肤病学   319篇
神经病学   2056篇
特种医学   708篇
外科学   3134篇
综合类   651篇
现状与发展   1篇
一般理论   27篇
预防医学   1569篇
眼科学   561篇
药学   1367篇
中国医学   43篇
肿瘤学   1491篇
  2023年   134篇
  2022年   269篇
  2021年   438篇
  2020年   297篇
  2019年   390篇
  2018年   495篇
  2017年   314篇
  2016年   411篇
  2015年   445篇
  2014年   606篇
  2013年   904篇
  2012年   1246篇
  2011年   1192篇
  2010年   747篇
  2009年   721篇
  2008年   1113篇
  2007年   1135篇
  2006年   1043篇
  2005年   1102篇
  2004年   1093篇
  2003年   1009篇
  2002年   922篇
  2001年   393篇
  2000年   379篇
  1999年   376篇
  1998年   242篇
  1997年   175篇
  1996年   179篇
  1995年   179篇
  1994年   131篇
  1993年   162篇
  1992年   255篇
  1991年   231篇
  1990年   247篇
  1989年   241篇
  1988年   229篇
  1987年   202篇
  1986年   215篇
  1985年   227篇
  1984年   188篇
  1983年   147篇
  1982年   153篇
  1981年   156篇
  1980年   132篇
  1979年   123篇
  1977年   99篇
  1976年   126篇
  1975年   106篇
  1974年   137篇
  1973年   110篇
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
1.
2.
Malignancy larynx usually presents early, the common symptoms being hoarseness, pain thorat, cough and irritation of throat. An advanced malignancy is likely to be complicated by a pharyngo-cutaneous fistula. However it is an occurrence towards the end stage of the disease. Here we present a case of malignancy larynx primarily presenting as pharyngo-cutaneous fistula without any other symptoms.  相似文献   
3.
Background Beating heart surgery has now become the commonest technique of doing Coronary Artery Bypass Graft Surgery (CABG) in our country. It is being used even in such high risk situations like diffuse coronary disease and Critical Left Main stem Stenosis (LMCS) with good results. The aim of this study is to retrospectively review our results in Off-Pump Coronary Artery Bypass Surgery (OPCAB) in patients with critical left main stem stenosis. Methods This study is a retrospective analysis of the data of patients who underwent primary coronary artery bypass surgery. During the period from April 2003 to September 2005 a total of 64 patients underwent OPCAB procedure for critical LMCS. During the same period 10 patients underwent CABG on Cardio Pulmonary Bypass (CPB). The age range was 36–77yrs. The sex distribution was M: F 53∶10. Ten patients were done as emergency. 2 of them were on Intra Aortic Balloon Pump (IABP) support preoperatively. 10 patients were high risk with a Euro score of ≥5. Results Left Internal Mammary Artery (LIMA) was used in 78% of cases. Average grafts per patient was 2.96. The median ventilation time was 5.91 hrs. New IABP insertion in postoperative period was required in 1 patient. One patient was reexplored for bleeding. There was one perioperative myocardial infarction. 57% of patients did not need any blood transfusion. There was no conversion to CPB. There was no operative mortality. Inotropes were used in ten cases. Conclusions OPCAB is a safe method of revascularization in patients with critical LMCS. Preoperative IABP is useful in patients with cardiogenic shock. However, there is a place for CPB in patients needing additional procedures like Mitral Valve repair (MV repair) or Dor's procedure or when the vessels are very diffusely diseased. Those patients who are unstable despite IABP support may be managed by Beating heart On Pump (BHOP) technique.  相似文献   
4.
5.
Mammalian fatty acid synthase (FASE) overexpression has been shown in a number of human malignancies including colonic adenocarcinoma. Since FASE synthesizes only saturated fatty acids, we hypothesized that cancer cells have a greater proportion of long-chain saturated fatty acids. We studied and found an unequivocal increase in saturated C18 fatty acid (stearic acid) in colonic adenocarcinoma compared to adjacent normal colonic mucosa. The increase is even more striking when measured as a ratio of stearic acid to the unsaturated C18 fatty acids (oleic acid and linoleic acid). This change in fatty acid composition of the cancer cells should significantly alter their physical and biological properties. The increase in relative proportion of saturated fatty acids should make the cancer cells more susceptible to cryodamage and measurement of fatty acid composition of cancer cells may help individualize the temperature for cryotherapy. Also, the lipid alterations may affect the structure and functions of lipid rafts, which may enable the cancer cells to affect signaling mechanisms such as those involved in cell growth and apoptosis. Dietary or therapeutic interventions targeting lipid rafts may thus be an option for cancer treatment.  相似文献   
6.
7.
8.
9.
Originally described by Rosen in 1983, syringomatous nipple adenoma (SAN) is a tumor of disputed histogenesis, which can be problematic both diagnostically and therapeutically. 1 It is a benign primary tumor of breast epithelium with histology similar to that of the syringoma. In the current case, we describe a 40-year-old female with this lesion occurring within a supernumerary breast. This case represents, to our knowledge, the first such reported case, and represents a significant finding as its presence could lend some confusion as to whether or not this represents a benign primary process of breast or a potentially infiltrative tumor of the skin.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号